Monthly archive for November, 2013

Have you ever heard the term “architecture” applied to the realm of software? Pretty sure you have. Our discipline, at least on the surface level, seems to borrow a lot of nomenclature from fields related to the construction of buildings. We talk about designs, frameworks, foundations, sometimes even scaffolds or facades.

And, of course, there is this whole convention of referring to programmers as “engineers”. Guess it simply sounds too good as a job title to let it go!

But frivolous as it may be, there is something deeply wrong about drawing analogies between erecting real structures and hacking virtual ones. It’s not even about attributing undue significance to the “mere” activity of sitting behind a screen and hammering at the keyboard; at this point, software development is probably at least as important as civil engineering – perhaps even more so.

The problem is that thinking of developing software as analogous to constructing buildings promotes flawed, unsustainable approaches. What is even more insidious is that they appear perfectly reasonable at first, mature even. It seems intuitively right, after all, to think of software project as something akin to construction project. In both cases you need to satisfy certain requirements, accommodate for interactions with external environment, and fit everything within time and/or budget constrains.

If it seems so right, then why it is so wrong? Well, because the similarity is only apparent, and thus largely superficial.

Design can only be arrived at by building

How common it is to begin construction of a building before its blueprint is finalized? Although few shovels might have tilled the ground here and there, construction engineers generally do not begin laying foundations until the structure’s design is ready. Before even the first bricks form a nascent wall, you can have pretty good idea of how the final thing will look like.

Can you say the same about software project? Certain methodologies (*cough* waterfall) claim to achieve almost the same degree of robustness and predictability, but most of us know how patently ridiculous they are. Not only is the final shape of system unknown when you start writing it, but it is practically unknowable. The design only reveals itself while you are already building, and this is something I’m sure would make the blood of traditional engineers run cold.

Laws of physics are of no concern

There are reasons for those unknowns, however. While real world engineering deals with real world limitations, bits and pixels are often completely unconstrained by those. More than by climate conditions, size of electromagnetic spectrum or the speed of light, software systems are limited by other, existing systems and processes: not necessarily software ones, but often unstable and changing.
As a result, dealing with them can get arbitrarily complex, not to mention that it transitively affects future systems interacting with us.

In comparison, the ground you build upon is quite literally rock solid.

Code is not concrete

Thankfully, there is one aspect of programming that makes all those obstacles somewhat surmountable. Unlike skeletons of skyscrapers, made of reinforced concrete, code is always modifiable. Regardless of how far you’ve progressed with current implementation, you can change and redesign it. Sure, there is typically a requirement to support outside clients through existing API but rarely, if ever, you are limited in how you’re gonna support them.

Frankly, this is something that I often see people struggling to come to terms with. Maybe because of those construction analogies I’ve mentioned, the structure of a program is often perceived as rigid and almost constant.
You are not allowed to tamper with it. You can only extend it in certain, predefined ways. And you better get it right the first time, as there is no going back. It’s almost as if the code was literally set in stone.

This, however, is a massive misconception. Code is meant to be poked and prodded; extended and removed; modified and reverted; and most importantly, hacked on and refactored. The notion of “technical debt” is a beautiful concept that captures all those mechanics. You don’t want to be in debt which is too large, because the interest rates (maintenance costs) will hinder you in the long run. But you also don’t want to have too small credit, or you won’t be able to make new investments (features) and expand your “business”.